net: xgene: Fix unused xgene_enet_of_match warning for !CONFIG_OF

Commit b0377116 ("net: ethernet: Use device_get_match_data()") dropped
the unconditional use of xgene_enet_of_match resulting in this warning:

drivers/net/ethernet/apm/xgene/xgene_enet_main.c:2004:34: warning: unused variable 'xgene_enet_of_match' [-Wunused-const-variable]

The fix is to drop of_match_ptr() which is not necessary because DT is
always used for this driver (well, it could in theory support ACPI only,
but CONFIG_OF is always enabled for arm64).

Fixes: b0377116

 ("net: ethernet: Use device_get_match_data()")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202310170627.2Kvf6ZHY-lkp@intel.com/


Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>